From e33286298591eb805a59a398667d247180c6395d Mon Sep 17 00:00:00 2001
From: Wim Taymans <wim.taymans@collabora.co.uk>
Date: Wed, 14 Mar 2012 16:27:31 +0100
Subject: [PATCH] pad: implement DRAIN handling

When we forward the DRAIN query and there is nothing to forward it to, assume we
are drained.
When a basesink receives a drain query, reply with TRUE.
---
 gst/gstpad.c                | 42 ++++++++++++++++++++++++++++++++++++++++--
 libs/gst/base/gstbasesink.c |  3 +++
 2 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/gst/gstpad.c b/gst/gstpad.c
index 9cafd95..ea4796a 100644
--- a/gst/gstpad.c
+++ b/gst/gstpad.c
@@ -2757,6 +2757,29 @@ filter_done:
   return TRUE;
 }
 
+typedef struct
+{
+  GstQuery *query;
+  gboolean result;
+  gboolean dispatched;
+} QueryData;
+
+static gboolean
+query_forward_func (GstPad * pad, QueryData * data)
+{
+  /* for each pad we send to, we should ref the query; it's up
+   * to downstream to unref again when handled. */
+  GST_LOG_OBJECT (pad, "query peer %p (%s) of %s:%s",
+      data->query, GST_EVENT_TYPE_NAME (data->query), GST_DEBUG_PAD_NAME (pad));
+
+  data->result |= gst_pad_peer_query (pad, data->query);
+
+  data->dispatched = TRUE;
+
+  /* stop on first successful reply */
+  return data->result;
+}
+
 /**
  * gst_pad_query_default:
  * @pad: a #GstPad to call the default query handler on.
@@ -2804,8 +2827,23 @@ gst_pad_query_default (GstPad * pad, GstObject * parent, GstQuery * query)
   }
 
   if (forward) {
-    ret = gst_pad_forward
-        (pad, (GstPadForwardFunction) gst_pad_peer_query, query);
+    QueryData data;
+
+    data.query = query;
+    data.dispatched = FALSE;
+    data.result = FALSE;
+
+    gst_pad_forward (pad, (GstPadForwardFunction) query_forward_func, &data);
+
+    if (data.dispatched) {
+      ret = data.result;
+    } else {
+      /* nothing dispatched, could be drained */
+      if (GST_QUERY_TYPE (query) == GST_QUERY_DRAIN)
+        ret = TRUE;
+      else
+        ret = FALSE;
+    }
   }
   return ret;
 }
diff --git a/libs/gst/base/gstbasesink.c b/libs/gst/base/gstbasesink.c
index 6dcdb91..151015d 100644
--- a/libs/gst/base/gstbasesink.c
+++ b/libs/gst/base/gstbasesink.c
@@ -4550,6 +4550,9 @@ gst_base_sink_default_query (GstBaseSink * basesink, GstQuery * query)
       res = TRUE;
       break;
     }
+    case GST_QUERY_DRAIN:
+      res = TRUE;
+      break;
     default:
       res =
           gst_pad_query_default (basesink->sinkpad, GST_OBJECT_CAST (basesink),
-- 
2.7.4